AUTHOR=Li Dong , Shi Fanpeng , Zhao Haisheng , Xiong Shaolin , Song Liming , Peng Wenxi , Li Xinqiao , Chen Wei , Ning Zongjun 

TITLE=Flare quasi-periodic pulsation associated with recurrent jets

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2022.1032099

DOI=10.3389/fspas.2022.1032099

ISSN=2296-987X

ABSTRACT=Quasi-periodic pulsations (QPPs), which carry time features and
plasma characteristics of flare emissions, are frequently observed
in light curves of solar/stellar flares. In this paper, we
investigate non-stationary QPPs associated with periodic jets during
an M1.2 flare on 2022 July 14. A quasi-period of ~45$\pm$10~s,
determined by the wavelet transform technique, is simultaneously
identified at wavelengths of soft/hard X-ray and microwave
emissions, which are recorded by the Gravitational wave high-energy
Electromagnetic Counterpart All-sky Monitor, Fermi, and the Nobeyama
Radio Polarimeters, respectively. A group of recurrent jets with an
intermittent cadence of about 45$\pm$10~s are found in Atmospheric
Imaging Assembly (AIA) image series at 304 {\AA}, but they are 180-s
earlier than the flare QPP. All observational facts suggest that the
flare QPP could be excited by recurrent jets, and they should be
associated with nonthermal electrons that are periodically
accelerated by a repeated energy release process, like repetitive
magnetic reconnection. Moreover, the same quasi-period is discovered
at double footpoints connected by a hot flare loop in AIA 94 {\AA},
and the phase speed is measured to ~1420 km s$^{-1}$. Based on
the differential emission measure, the average temperatures, number
densities, and magnetic field strengths at the loop top and
footpoint are estimated to ~7.7/6.7 MK,
~7.5/3.6$\times$10$^{10}$ cm$^{-3}$, and ~143/99~G,
respectively. Our measurements indicate that the 45-s QPP is
probably modulated by the kink-mode wave of the flare loop.